/*
** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com)
**
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of version 2 of the GNU Library General
** Public License as published by the Free Software Foundation.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** Library General Public License for more details.  To obtain a
** copy of the GNU Library General Public License, write to the Free
** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
** Any permitted reproduction of these routines, in whole or in part,
** must bear this legend.
**
**
** map160.c
**
** mapper 160 interface
** $Id: map160.c,v 1.2 2001/04/27 14:37:11 neil Exp $
*/

#include <noftypes.h>
#include <nes_mmc.h>
#include <nes_ppu.h>
#include <nes.h>

static struct
{
    bool enabled, expired;
    int counter;
    int latch_c005, latch_c003;
} irq;

static void map160_write(uint32 address, uint8 value)
{
    if (address >= 0x8000 && address <= 0x8003)
    {
        mmc_bankrom(8, 0x8000 + 0x2000 * (address & 3), value);
    }
    else if (address >= 0x9000 && address <= 0x9007)
    {
        mmc_bankvrom(1, 0x400 * (address & 7), value);
    }
    else if (0xC002 == address)
    {
        irq.enabled = false;
        irq.latch_c005 = irq.latch_c003;
    }
    else if (0xC003 == address)
    {
        if (false == irq.expired)
        {
            irq.counter = value;
        }
        else
        {
            irq.expired = false;
            irq.enabled = true;
            irq.counter = irq.latch_c005;
        }
    }
    else if (0xC005 == address)
    {
        irq.latch_c005 = value;
        irq.counter = value;
    }
#ifdef NOFRENDO_DEBUG
    else
    {
        log_printf("mapper 160: untrapped write $%02X to $%04X\n", value, address);
    }
#endif /* NOFRENDO_DEBUG */
}

static void map160_hblank(int vblank)
{
    if (!vblank)
    {
        if (ppu_enabled() && irq.enabled)
        {
            if (0 == irq.counter && false == irq.expired)
            {
                irq.expired = true;
                nes_irq();
            }
            else
            {
                irq.counter--;
            }
        }
    }
}

static void map160_init(void)
{
    irq.enabled = false;
    irq.expired = false;
    irq.counter = 0;
    irq.latch_c003 = irq.latch_c005 = 0;
}

static map_memwrite map160_memwrite[] = {{0x8000, 0xFFFF, map160_write}, {-1, -1, NULL}};

mapintf_t map160_intf = {
    160,                /* mapper number */
    "Aladdin (pirate)", /* mapper name */
    map160_init,        /* init routine */
    NULL,               /* vblank callback */
    map160_hblank,      /* hblank callback */
    NULL,               /* get state (snss) */
    NULL,               /* set state (snss) */
    NULL,               /* memory read structure */
    map160_memwrite,    /* memory write structure */
    NULL                /* external sound device */
};

/*
** $Log: map160.c,v $
** Revision 1.2  2001/04/27 14:37:11  neil
** wheeee
**
** Revision 1.1  2001/04/27 12:54:40  neil
** blah
**
** Revision 1.1  2001/04/27 10:57:41  neil
** wheee
**
** Revision 1.1  2000/12/27 04:24:46  matt
** initial revision
**
*/
